A few years ago, the automotive industry began to reverse the trend, which it had begun almost twenty years before, of replacing dashboard gauges with small warning lights or so-called "idiot lights". In part this was due to the sophistication of electronic gauges. Electronics are now used in various subassembly components of the modern day vehicle instrument panel. Electronic modules are used as small on-board computers that monitor hundreds of inputs from various sensors on the vehicle. Many leads or wires are used to electrically convey information from sensors at the sources of the information to the electronic gauges, through relays monitored by the modules. Other electronic subassemblies, such as radios, message centers, power antennae relays, intermittent windshield wiper controls, electronic air conditioning switches and relays, and other subassembly components are also interconnected by leads and wiring to electrical sources and sensors.
Because of the sheer number of electrically conductive wires used to electronically connect the subassembly components to each other and to other vehicle electrical components, wiring harnesses are typically used to arrange the conductive wires in groups. The wiring harnesses are attached to the instrument panel and routed along its substructure during assembly of the board or instrument ! panel. Wiring harnesses have the advantage of bringing some order to a spaghetti-like entanglement of wires, facilitating some tracing of the wires to allow for proper connections during assembly and to allow for trouble-shooting such connections for repair.
While wiring harnesses have advantages over loose arrays of wires that are difficult to trace, wiring harnesses also have shortcomings. Manually attaching and routing the wiring harnesses is a tedious and labor intensive task. Furthermore, owing in part to the tediousness and labor intensiveness of the task, manual manipulation of the wiring harnesses during assembly often results in damage to the instrument panel, to the subassembly components, and to the wires themselves. Because of the number of subassembly components that must be electrically interconnected, it is of limited advantage to systematize the deployment of wires simply by restraining wires as is done by using wiring harnesses.
For example, bunching a number of wires in a wiring harness does not help in allowing work operations to be performed upon the ends of the wires. This shortcoming can be appreciated by considering the teaching of U.S. Pat. No. 3,956,822, issued to Folk on May, 18, 1976. Folk discloses a method and apparatus for positioning lengths of individual leads of a plurality of leads in spaced-apart relationships with respect to one another, so that work operations can be simultaneously performed on the ends of the leads. The lengths of leads are positioned in a plurality of spaced-apart grooves of a template by progressively positioning successive parts of the lengths of each of the plurality of leads into respective grooves. Each groove is wider and deeper than the leads positioned within the groove. Each of the grooves has one or more spaced-apart lead confining means that retain segments of the leads positioned in the groove. The template with its grooves are only employed to perform the work operations on the ends of the leads. When the work operations are complete, knockout pins are associated with each of the spaced-apart lead retaining means to facilitate stripping the leads from the template. Accordingly, a wiring harness does not facilitate end operations of leads, such as the installation of terminals, As disclosed in the related U.S. patent application entitled "Wiring System for Automotive Instrument Panel Wire", cited in the Cross Reference to Related Applications section of this specification, a system of grooves or troughs as used in the present invention has advantages over both work templates and wiring harnesses.